Page:Proceedings of the Royal Society of London Vol 60.djvu/471

Rh hot funnel, at this temperature; the filtrate was cooled to about 0° C. and the precipitate collected, dissolved in ether, recovered therefrom, and weighed; the weight, compared with the volume of the filtrate, gave a measure of the solubility.

3. To a series of equal volumes (10 c.c.) of bile in test-tubes, a rising series of weights of fatty acids was added (0.05, 0.1, 0.15, 0.2, &c., grams), and those tubes noted, in which, after the lapse of a sufficient time at 39° C., complete solution did not take place.

The following is a summary of our results.

The fatty acids are not dissolved as soaps, but probably as fatty acids, for the solution becomes strongly acid; moreover, the material thrown out on cooling dissolves easily in ether, and, when recovered, saponifies at once with sodium carbonate. The solution is not entirely due to the bile salts, for mere removal of the “ bile mucin ” greatly diminishes the solvent power, although the “mucin” redissolved in sodium.carbonate solution has no solvent power, and, again, a solution of mixed bile salts stronger than bile has not nearly so much solvent power as the bile itself.

Palmitic and stearic acids are very feebly soluble in bile at 39° C., and in mixtures are probably dissolved by the aid of the admixed oleic acid.

The filtered intestinal contents contain both pancreatic juice and bile, and hence should both decompose and dissolve fats at body temperature if these are absorbed as dissolved fatty acids; this was experimentally found to be the case with filtered intestinal contents of the dog, which in different cases possessed a very variable


 * The numbers given are the minimum and maximum of a number of determinations in different samples of bile.

t The solution used was a 9 per cent, solution of the bile salts of a sample of ox bile which dissolved 2'5 per cent, of the fatty acids of beef suet; this solution oi bile salts only dissolved 1 per cent.